Evidence for a T-cell related factor as the cause of demyelination in mice following Semliki Forest virus infection.

Patchy demyelination throughout the central nervous system, including the optic nerve, is known to occur following infection with Semliki Forest virus (SFV) in Swiss/A2G mice. An increase in the fast axonal transport of protein in optic nerves occurred before they showed signs of demyelination in Swiss/A2G mice, heterozygous nude mice and nude mice reconstituted with T-cells. SFV infection, however, caused neither an increase in the fast axonal transport of protein, nor optic nerve demyelination in T-cell-deficient nude mice. Thus, the increase in both axonal transport and demyelination following SFV infection appear to be T-cell-mediated events, rather than direct effects of the virus.